Electric-arc lamp



Nov. 25, 1930. w. c. SPIETH ELECTRIC ARC LAMP Filed Sept. 10 1925 3 Sheets-Sheet l anugntoz rll Nov. 25, 1930. w. c. SPIETH ELECTRIC ARC LAMP Filed Sept. 10" 1925 5 Sheets-Sheet 2 a 0 M L 9 a a 1 2 4 Z fg w ]l|l14|l 5 3 J. i w 4 1 m e W W $2 OM/0M6 Nov. 25, 1930.

W. C. SPIETH ELECTRIC ARC LAMP Filed Sept. 10, 1925 5 Sheets-Sheet 3 Patentecl Nov. 25, 1930 UNITED STATES PATENT oFFiE WILLIAM C. SPIETH, OI GENEVA, OHIO ELECTRIC-ARC LAMP This invention relates to electric-arc lamps,

and particularly to lamps having a luminous or flaming are, which lamps are especially adaptable for blueprinting, photo engraving, photo-lighting, and photo-chemical reactions.

The primary object of the present invention is to provide a lamp which will pro duce a great volume of illumination of exceptional brilliance and actinic value.

Another object of the invention is the provision of a lamp that gives a maximum of illumination or lighting efiiciencywith a minimum amount of current, consumed.

A further object of-the invention is to provide an intensified are giving a great volume of illumination with an economical operation, so that a highly efficient plant may be maintained at comparatively low cost.

2 Anotherobject of the present invention is to provide an arc lamp construction that can be used as a complete lighting unit, and selfcontained blue-printing equipment.

Among the novel features of the construction is the arrangement for automatic electrode adjustment, whereby the arc is maintained uniform with the production of a steady flame.

Other features are the arrangement and operation of the magnet coils, the construction and arrangement of the armature provided with an armature spring connection, and the provision of an air-pot and air-pot yoke construction for the insurance of a uniform, steady flame. Further features are the top construction, providing for a three wire system between the lamp and rheostat, also a center tubular carbon holder and carbon cable.

Other important factors are the carbon clutch, the arrangement of a heat shield and other insulating elements.

The invention further provides a reflector soconstructed and arranged that it is efficient and convenient for use in blue-printing and photography, providing ready access for lamp trimming, and allowing an air pocket back of the lamp and drafts in front, there by cushioning both the front and back of the lamp and intensifying the light.

The invention further provides a multiple unit resistance with a dial so constructed that provision ismade for three wire system to give super-efliciency in addition to the two terminals provided for in the line service. The rheostat is so constructed that it acts as a booster providing a direct ratio of increase in illumination as the square of the added amperes from its lowest to its highest point.

This rheostat is adaptable to any amperage either for direct or alternating current on either 110 or 220 volts service of enclosed or open arc lighting service.

This special construction, with its arrangement of elements and peculiar windings is adaptable to all single arc lamps either of enclosed or open arc type, using the enclosed arc carbons of the cored, or solid type, or cored open arc white flaming carbons for blue-printing and other photo-chemical processes.

The various features of novelty constituting the invention will be hereinafter especially pointed out in the claim, but for a full understanding of the invention in its various aspects, reference is to be had to the following detailed description taken in connection with the accompanying drawings wherein Figure l is a front elevation of the improved lanip without the reflector and rheostat onnections.

Fig. 2 is a side elevation of the bare lamp.

Fig. 8 is a front elevation of the lamp with the reflector and other accessories attached, but with a part of the reflector broken away.

. is a side elevation.

5 1s a top view of the reflector. I" i o 1 s a diagrammatic View of the three respectively, and the lower terminals are connected by a yoke 9 provided with a socket 9 which supports the carbon electrode 10, said carbon being adjustably held therein by a set screw 11. The housing a alsosupports a horizontally disposed disk 12. Said disk is composed of heat resisting or opposing material, such as hard asbestos, or vitreous matea nd acts to protect the upper parts of the rial, lamp from theh'eat of the are which is formed at A] The upper movable electrode 13 is slidablev in the tube 3 and has a clasp 14 clamped thereto, the clamp 1 1 of said clasp extending through a vertical slot 8 in the tube 3, and providing for the connection of the conductor 15.- Theconductor 15 is connected with the positive binding post 18 through an intermediate binding post 16 and a conductor 17 A two spool solenoid 19, of heavywinding, is supported by the canopy 1 and is connected through the binding post 16 with the conductor 17, and through the binding post20 and conductor 21 withthe positive binding post 22. The cores of the solenoid are connected at their lower ends by across-bar thereby forming a U-shaped core? frame 23. The frame 23 is mounted upon the upper member of an elliptical spring 24, and the lower member of said spring is pivotally connected with a clutchrrod 25. The clutch-rod 25 passes through a fixed guide bracket 26, and is pivotally attached, at its lower end, to the carbon-clutch 27 disposed overthe heat shield 12.

For the purpose of controlling the move ment of the cores withln'the spools of the so-.

lenoid,'and to insure a slow and steady movement when the solenoid is acting to separate the carbons, an air-pot 28 is provided, and a rod 29 is connected with the plunger of said air-pot and extends downward to a bearon top of the carbon-clutch 27. v

The current entering the lamp flows from the positive binding posts 18 and 22 to the binding post 16 one part directly through the conductor 17 and another part through the conductors 21 and 19 and the solenoid 19, and then from the binding post 16 by conductor 15 to the upper carbon 13, thence to the lower carbon 10, thence by yoke 9, rods 8, and conductors 6 and 6, through cable 6 to the negative binding-post 7 For blue-printing and photography a reflector 30 is provided. Said reflector is 7 formed as shown in Figs. 3, 4, and 5, and is attached to the lamp by means of flangedsleeves 5O which clasp the insulating sleeves 8 on the rods 8. The reflector extends forward from the supports 8, flaring outward to an open front oflarge area, and is provided with apertures 30? in the top and bottom in juxtaposition to the front. A semi-circular reflecting member 30 is hinged to the member 30, as shown at 30 and extends back of the lamp, a fragmentary bottom 30 providing an air-pocket back of the electrodes. This member 80 being hinged to member 30 provides convenient access to the electrodes for trimming. J r

A cup 31 suspended from the yoke 9 providesa receptacle for carbon dust, scale, and other extraneous particles which may descend from the lamp.

Fig. 6 illustrates, diagrammatically, the hook-up of the three wire system in connection with the rheostat and special dial. In

the present embodiment a ten-fold resistance.

32 is connected with a dial 33'by conductors 34:. Two positive terminals 36 and 37, and one negative terminal 35, are carried on the dial 33. Aconductor a extends from the terminal 35 to the lamp connection 7 and through con ductor 6 to the lamp frame or lower carbon support. The conductor Z) extends from the terminal 36 to'the lamp connection 18, and through conductor 17 and binding post 16 and conductor 15 to the upper carbon holder 3.

Conductor 0 extending from terminal 37 to lamp connection 22 is connected with the upper carbon holder 3 through conductor 21 and the solenoid 19 and conductor l9 'and binding post 16 and conductor15. Lines 6 and'c are shunted to the resistance 32 by conductors 38 and 89. The amount of resistance is governed by the rotary switch, 40 acting on the contact plates 41. V I

This connection of the two positives b and 0 with the resistance 32 acts as a booster pro,-

viding a direct ratio of increase in illumina-. tion as the square of the added amperes from its lowest to highest point, 14 to 50 amperes on 110.votes and 7 5 to 25 amperes on 220 volts.

From the above description it W111 be apparent to those skilledin the art that on the initial points of the rheostat the arc is in series with the solenoid, and the solenoid regulates the gap in response to the current-flow, in the usual manner, and that that part of the current always does flow to the lamp through the solenoid, but that the additionalcurrent flow} ing upon the: advance of the rheostat arm-to cover additional points flows through the conductors 6 and 18 directly to the binding its ifs

post 16 and uppercarbonholder 3 without passing through the solenoid 19, and it will therefore be understood that this additional current does not operate to lengthen'the arc gap, so that, by movement of the rheostat beyond'the initial points, I may pass additional; current through the are without change in the length of the gap, to thus greatly increase the,

power of the gap, and the illumination from the arc.

What I claim and desire to secure by Letters Patent is:

A reflector, for use with an arc lamp of a type having vertically extending members flanking the are on the two sides of the arc, serving as conductors to the lower electrode, and surrounded by insulating sleeves, comprising a top, a base, and a lateral wall con neoting said top and said base, and provided with means adapted to clamp said sleeves to hold said reflector supported on said lamp.

In testimony whereof I aflix my signature,

, WILLIAM G. SPIETH. 

